The invention relates to a system for guiding cable, including, for example, heavy-duty, high-voltage cable, round a bend.
U.S. Pat. No. 6,109,561 (Haines Cable Systems) shows a system for guiding bundles of cables using rollers, and may be referred to for background.
When installing cable in a plant, in particular in a generating station such as an offshore wind-power station, cables have to be laid connecting the output to the distribution network. Laying such cables in a straight line is not difficult, and for this purpose clamps such as those set out in the applicant's EP 1973211 A1 can be used in certain implementations. Cable is unwound from a drum and advanced using a suitable drawing machine, and laid on the individual cleats. The cleats can have a roller at each end, so that the cable can run on these rollers, held in by hoops around the cable, until it is in its final position, whereupon the rollers are removed and the cable drops into the cleat. The cable can then be clamped in position in the usual way.
For guiding the cable round a bend, however, additional problems arise. Such bends arise for instance where the cable has to drop down or rise up a level in the plant or rig. High-voltage cables typically have a diameter of the order of 100-160 mm, and can be bent round a curvature or radius of approximately 3 m. This makes it difficult, if not impossible, to insert the end of the cable through both roller hoops on a typical cleat, because the curvature is too great. One way of guiding the cable round a bend therefore has involved installing bespoke roller guides fastened to the structure, and then removing them when the cable is in place and installing bespoke cleats to hold the cable in the bend region. This is obviously inconvenient in itself, and moreover the rollers have to be stored somewhere once they have been used.